Standard tuning. Occasionally dropped-D, and occasionally lute-tuning (EADF#BE). I use a classic guitar, and cranking it up and down wreaks havoc on a set of nylon strings and it's not all that good to keep changing the tension on the soundboard. Also, I hate having to keep tuning and re-tuning. Get it in tune and weld it!

Your mileage may vary.

Don Firth